System of motor control.



N0. 830,158. PATENTED SEPT. 4, 1906. A. MAGNUSON. SYSTEM OF MOTOR CONTROL,

APPLICATION FILED JULY 6. 1905.

2 SHEETS-SHEET 1 &

934W fva PATENTED SEPT. 4, 1906.

A. MAGNUSON. SYSTEM OF MOTOR CONTROL.

APPLICATION FILED JULY 6, L905.

2 SHEETS SHEET 2.

p which show in 30 device.

UNITED STATES PATENT OFFICE.

AXEL MAGNUSON, OF=NEW YORK: N. Y., ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY OlTY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SYSTEM OF MOTOR CONTROL.

I Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed July 6, 1906. Serial No. 268,692. I

and State of New York, have invented certain new and useful Improvements in Systems of Motor Control, of which the following is a specification.

My invention relates to a system of motor iofcontrol; and it consists of a novel arrangement of various apparatus and circuits whereby an electric motor may be started, stopped,

and otherwise controlled at will.

Although my system is applicable to other :5 types of electric motors, it may be used to great advantage in conjunction with such motors as are operated by alternating currents.

I have made application for Letters Pat 2o ent, Serial No. 241,592, filed January 18,

1905, for a system of motor control which embodies the broad idea of the present invention, and the present invention is of certain improvements and developments of the inven- 2 5 tion disclosed in said prior application.

to the drawings, Figure 1 is a certain apparatus and circuits invention. Fig. 2 is an end view of a detai of a controller or accelerating Fig. 3 is a sectional view of an actuator which may be used in connection with the motor-accelerator. Fig. 4 is aside elevation of an electrornagnetically-actuated brake, and Fig. 5 is a wiring diagram of a se Referrin diagram 0% riesenerat'or'with means for reversin the armature connections.

Like characters of reference designate corresponding parts in all of the figures.

" 'd'esi ates an electric motor which is to be contro ed; In the drawings it is'shown as an alternating current motor. I

f 20 is a generator connected to run with the motor. It may be directly connected to the motor b having its shaft 21 connected to the motor-s aft 11 by means of a cou ling 22, or it may be connectedin any pt or desired manner.

'30 is ,a brake for the motor. It comprises an electromagnet 31, which may be rovided 5 with two separate windings 32 an '33. i It also comprises a brake-band 34, which is ar- {ranged to be tightened about the coupling 22 by means of a spring 35 and released by the pass through fuses 44 and a main switch 45.

designates an electromagnetically-actuated reversing-switch for starting the motor in either direction. It comprises two magnets 51 and 52, each of which is rovided with two energizing-coils 51 51 an 52 52 53 designates the core for magnet 51, and 54 the core for magnet 52. Connected to but insulated from these cores are certain movable contacts 53 53 and 54 54 Above these movable contacts are stationary contacts 53 53 and 54 54 The main 41 is connected to contacts 53 and 54 and the main 43 is connected to contacts 53 and 54. Contacts 53 and 54 are connected to motorterminal 12, and contacts 53 and 54 are connected to motor terminal 14. When magnet 51 is energized andraises its core 53, contacts 53 and 53 will be closed against contacts 53 and 53 and thereby the main 41 will be connected to motor-terminal 14 and main 43 will be connected to motor-terminal 12. The main42 is connected to the central motor-terminals 13, and therefore the motor will receive current from the line and will begin to rotate in one direction. When magnet 52 is energized and lifts its core and its connected contacts, the mains 41, 42, and

43 will thereby be connected to motor-terminals 12, 13, and 14, respectively. The motor will then receive current from the line in the other direction and will rotate in the other direction.

Before pointing out the electromagnetic means for actuatin this reversing-switch or starting-switch 50 will show how it may be actuated by hand. An actuating-lever 55 is rovided with a hang It is evi ent t at the cores 53 and situated above the magnets 51 52 and is piv- IOO tuated in the desired direction b a movement of the lever 55, and, if desire the electromagnetic means may be so designed as to be inoperative to close the switch; but after it is closed manually, as described, the electromagnetic means may be efiective to hold said switch closed, or the manual means for closing the reversing-switch may be entirely in switch may be manually operated from a distance.

Springs 55? may be provided to bring the lever 55 back to central position when released. The lever 55 carries at one end two contacts 55 and 55,which are ar-,

' ranged to be moved against stationary contacts 55 or 55 55 whenever the lever. 55 is moved either by hand or by the magnets 51 52. These contacts control certain plectrical contacts, which will be pointed out ater.

' 70 designates a storage battery which is connected to various parts of the apparatus in a manner which will be specifically described presently.

is a manuall -operated master-switch, by means of whic the'motor may be controlled through the intermediate a' ency of other devices. This master-switc comprises a contact-arm 61, which is pivoted at 62 and which carries two contact-plates 63 and 64. Whenthe arm 61 is moved to the right, its contact-plate 63 bridges and electrically connects two stationary contacts 65 and 66, and thereby completes a circuit from the battery through conductors 71 73, magnet-winding 52 conductor 74, contacts 81 and 81 on a controlling device, (which I will describe more in detail later,) and conductor 72 back to the battery 70. The battery-circuits are shown by light lines with dots upon them. It will be seen, then, that magnet 52 will be energized by the battery-current, and it will raise its core 54, with its con nected contacts. This will cause the motor 10 to rotate in one direction, as I have already shown. It will also cause the lever 55 to be moved so that its contact 55 will be closed against contact 55. This will close a circuit through conductors 71 75 76, brake-magnet coil 32, and conductors 77 74, contacts 81 and 81, and conductor 72 to .the battery. The battery-current will 'then energize the brake-magnet, and it through its connected mechanism will release the brake 30. At the same time contact 5.5 on lever 55 will be closed against contact 55 Contact 55* is connected to the generator 20 by one of its 4 mains 24, and a circuit will now be closed through this main 24, conductor 24, brake- As the motor rotates it ter will generate a voltage proportional in stren th to the speed of the motor. Its generated current will cooperate with the battery-current to energize magnet 52 and the brake-magnet 30. The'strength of thegenerated current may be regulated at will by means ofa regulating-switch 25. This comprises a pivoted arm 25, which is arranged to be moved across a series of contacts 25 to which the resistance 25 is connected. By moving the arm 25 more or less of this resistance may be inserted in the generatorcircuit. A cut-out switch 100 may also be provided to make or break the gene'rator-circuit at will.

I will now describe the motor accelerator or controller 80. This is a barrel or drumswitch of a common type, which comprises a rotatable base 82, upon which are mounted a number of electrical contacts, such as 83 83 83. This base may be rotated about a shaft 84 in such a manner as to bring its connected contacts under and in contact with certain stationary brushes 85 86 87. This may be accomplished directly by hand by means of a hand-wheel 88 or from a distance by hand by means of a hand-wheel 88 which is connected to another wheel or pulley 88 on the-shaft 84 by means of a belt or chain 88. This movement of the base 82 may also be accomplished by means ,of a magnetic actuator 90, which may be constructed as shown in the drawings. It is there shown as comprising a solenoid-coil 91, in which are several magnetic cores 92, 93, and 94. These coresare preferably of different lengths and are placed in different positions within the coil 91. They may be connected to .a shaft 96 by means of rods 95, arms mounted loosely on the shaft, and stop-pieces 98 rigidl attached to the shaft. Means may be provi ed to hold these cores in raised position when the coil 91 is not excited. I have shown a weight 97% and a spring 97 'within a casing 97 and attached to a pulley 98 on shaft 96 by means of a strap 99 for this purpose. The shaft 96 of the actuator may be directly'connected to the shaft 84 of the accelerator.

I will now describe theoperation of this device. The coil 91 is connected directly across the generator through the main 24, conductor-24, and main 23, conductors 24,

' 24 and 24. As the generator is driven by vto the. speed of the motor.

farther wit the influence of the ma the motor it will send a current through this coil 91 which will be proportional in strength Consequently the coil 91 will exercise an increasing pull on the cores 92, 93', and 94 as the motor accelerates. As core 92 is placed farthest within the coil 91, it will be the first to respond to its influence. It will move the shaft 96 a certain amount and at the same time will cause the cores 93 and 94 to be moved farther into the coil 91. The core 93 will then be in position to respond to a further increase of magnetic pull, which the coil will have as soon as the motor has speeded up a certain de ee. This will pull the core 93 etic lines of the coil 91, and when the coi 91 is sufficiently1 excited it will .pull the core '94 down. T us'it will appear that as the excitation of coil 91 increases the shaft 96 of the actuator will be moved step bystep in one. direction and through its connected mechanism will cause the motor-accelerator 80 to be correspondingly moved step by step. This operation may be reversed by weakening the current in coil 91, when the weight 97 and the spring 97 will cause the shaft 96 and its connected parts to move step by step in the opposite direction.

I will now refer again to the motor-accelerator 80 and will point out that when it has been moved one step, either by hand or by the actuator 90, its brushes 85 will connect and short-circuitthe contacts 83, 83 and 83 The second step of its movement is arranged to short-circuit a similar set of contacts 89 89", and 89 by means of the stationary brush 86. Similarly the third step of its movement will cause the contacts 16, and 17 to be short-circuited by the stationary brush 87.- An opposition element 18 may be connected in the motor-circuit. This opposition element may,.be resistance, inductance, or any other desired arrangement to prevent the starting-current of the motor from being too great. It is shown as a star-connected resistance, the

ends of which, 15, 16 and 17 are con-,

nected to the rotor of the. motor 10 by means of conductors 15, 16, and 17. Intermediate points-on the resistance are connected to contacts mounted u on the base 82 of the accelerator or control er 80, as shown, and the apparatus is so arranged thatvwhen the accelthe motor. At the same time the acceleraerator is moved step by step as the speed of the motor increases, as already described, the resistance will be short-circuited step by step. This is a desired operation as the resistance will thus be cut out of the motorcircuit in proportion to the acceleration of F tor has been moved its last step, so that its stationary brush 87 electrically connects contacts 15 16, and 17 and the stationary contact or brush 81 will run off of contact 81, which is mounted upon the base 82, and will run onto another contact 81 which is also mounted upon the base 82. This will break the circuit between conductors 72 and 74, and will thus out off the battery-current from magnet 52 and brake-magnet 32. This may be done automatically by the current from the generator acting upon the coil 91 of the actuator. When the generator-current has attained suflicient strength to accomplish this, it is also strong enough to energize magnets 52 and 32 without the cooperation of the battery-current. This is simply a matter of adjustment. One of the generator-mains 24 is connected to one side'of the battery through conductors 24 and 71. Theother generator-main 23 is connected through resistance 25 conductors 24 24 24, and 24 to the contact 81 Now when contacts 81 and 81 are together the generatormain is thereby connected to the battery 70 through conductor 72. The generator 20 will thus charge the battery during the subsequent running of the motor. To accomplish this, the generator-current should always flow in one direction regardless of the direction of rotation of the generator. Fig. 5 shows an arrangement for reversing the connections of the generator when its direction of rotation is reversed, so that its gen erated current will always flow in one direction. In this View, Fig. 5, an arm 28 is shown, the lower end of which is supported by the armature-shaft 21 and is pressed against the shaft by a spring 28, the tension of which may be adjusted by a nut 28 The other end of the arm carries two contactpieces 26- and 27, which are insulated from each other and from the arm 28. The outgoing conductor 23 is connected to contactpiece 27, and contact-piece 26 is connected to one end of the series field 20 The other outgoing conductor is connected to the other end. of the series field. Contact-pieces 26 and 27 rest upon stationary contacts 29 and 29*, respectively, as shown, or else upon sta- The'armature-brush 20 is connected to stationary contact 29, and the armaturebrush 20 is connected to the other two stationary contacts 29 and 29 When the motor 10 drives the shaft 21 to the left, the arm 28 and contact-pieces 26 and 27 will remain in the positionshown with arm 28 resting against a stop 28 but when the shaft 21 is rotated to the ri ht the arm 28 and the contact-pieces will until the arm reaches the stop 28 when contact-piece 26 will rest upon stationary contact 29 and contactpiece 27 will rest upon stationary contact 29*. This will e carried over thereby cause a reversal of connections betweenthe armature and fields and will cause the gen,,

erated current to flow in the same direction through the fields of the enerator and its 5 outgoing conductors regar less'of the direction of rotation of the shaft 21.

At 45 in Fig. 1 I have shown an arrangement for cutting off the current from the motor should its speed become excessive. A main switch having pivoted arms 45' is arranged to be closed by hand by means of a handle 45. A magnetic core 45 is also connected to these pivoted arms and is laced within a solenoid-coil 45. This coil 1s connected across the generator by being connected to the main 24 and to the conductor 24"", which is connected to the other main. The arts may be so adjusted that when the v0 tageof the generator becomes excessive on'accountof the motor running too fast the coil 45 will attract the core 45', and thus pull 0 en the main switch.

I have descrlbed the operation of this system for operating the motor in one direction. If the pivoted arm 61 of the motor-switches is brought back to center, it will break the controlling-circuits, and thus cut off current from the motor and the brake and cause the motor to stop. If the arm 61 had been moved to the leftinstead of to the right, so that its contactplate 63' bridged contacts 65 and 67 and its contact-plate 64 bridged contacts 68 and 69,

the operation would have been similar; but

in this case magnet 51 would have been energized and the motor would rotate in the opposite direction. This reverse operation can of course be obtained by hand.

This system is'capable of many applications and may be used to control various types of motors. The battery maintains the current at a practically constant value for starting the controlling system, and the variable volta e is used to automatically control the acceIeration of the motor. Furthermore, after the motor has attained full s eed, and conse uently the generators v0 tage has reache considerable strength, its cur-' rent is not onl used to maintain the various apparatus in the desired positions, but is also used to charge the storage battery. I believe that I am the first to connect a generator to a motor and to use the-current from such generator to control all the movements of the motor. 5 5 In electric railroad or elevator systems or in other cases where it is desired to control the movements of motors from a distance this system is of greatvalue. This is because mechanical means are provided to supplement the electrical means for operating the motor. This is a safeguard,-as the operator will always be able to control the motor, even if the electrical o erating devices should not be in working or er. 6 5 v I have shown the magnetic actuator connected to an accelerator or controlling device which controls the acceleration of the motor through the intermediate agencyof a resistance or other opposition element. It may be connected to any other suitable arrangement or apparatus for controlling the motor, which apparatus may be diflerent with the various types of motor used. It is also obvious that two or more motors may be controlled simultaneously from one masterswitch.

What I claim is 1. In a system of motor control, a motor, a battery, three sources of current-supply, one of which is led to the motor, another of which is generated by the movement ofthe motor, and the third 'of which is in said battery and is derived from said second source of supply, said three sources of supply adapted to control the motor.

2. In a system of motor control, a motor, a starting-switch therefor, one source of electrical supply ada ted to actuate the startingswitch, a secon source of current-su ply adapted to drive the motor, and a. t (1 source of current-supply adapted to automatically control the acceleration. of the motor. V

' 3. In a system of motor control, a motor, a reversing-switch therefor, one source of cur- 95 rent-supply adapted to actuate the reversingswitch, a'second source of current-supp y adapted to drivethe motor, and a generator I driven by the motor and arranged to generate a variable current proportional in strength to the speed of the motor, said variable current being arranged to control the acceleration of the motor in proportion to its strength.

4. In a system of motor control, a motor, a battery, a starting-switch for the motor, a current-supply derived from said battery for actuating t e starting-switch, a sourcev of current-supply adapted to drive the motor, and afenerator driven'by the motor and ar- 1 10 range to. generate a current, said current arranged to charge the battery.

5. In a system of motor control, a motor, a battery, a reversing-switch for the 'motor, a current-sup ly derived from said battery for 1 15 actuating t e starting-switch, a source of current-supply adapted to drive the motor, and a generator driven by the motor and ar ranged to generate a current, said current arranged to control the acceleration of the 120 motor and to charge the battery.

6. In a s stem of motorcontrol, a motor,

a brake, a battery, a starting-switch for the motor, a current-supply derived from sald battery for actuating the starting-switch and 1 2 5 thebrake, a source of current-supply adapted to drive the motor, and a generator drlven ated switch arranged tocontrol the batterycurrent.

8. The combination with a motor, of a controlling system therefor, a generator connected to run with the motor, an additional source of current, and means dependent upon said generator and said. additional source of current for operating said controlling system. 9. The combination with a motor, of av controlling system therefor, a primary source of current dependent upon the motor, a secondary source of current dependent upon' said primary source, and means operated entirely by the current from said sources for operating said motor-controlling system.

10. The combination with a motor, of a controlling system therefor comprising a starting-switch, a generator connected to run with the motor, an additional source of current, and connections between said generator and said additional source of current and said motor-controlling system.

11. The combination with a motor, of a controlling system therefor, a generator connected to run with the motor, a secondary source of current dependent upon said generator, and means operated by the current from said generator and secondary source of current for operating said controlling system.

12. The combination with a motor, of v a controlling system therefor, comprising an electromagnetic actuator, a generator connected to run with the motor, an auxiliary source of current, and connectionsbetween the generator, auxiliary source of current and said controlling system.

13. The combination with, a motor, of a controlling system therefor comprising a starting-switch, a generator connected to run with the motor, a secondary source of cur- .rent, connections between the controlling system, generator, and secondary source of current, and a manually-operated circuitcloser' for said generator. I

14. The combination with a motor, -of a controlling system therefor comprising an electromagnetic actuator, a primary source of current dependent upon the motor, a secondary source of current dependent upon said primary source, means operated entirely by the current from said sources for operating said motor-controlling system, and a switch for closing the circuit of the generator.

15. The combination with a motor, of a controlling system therefor comprising a brake, a generator connected to run with the motor, an additional source of current dependent upon said generator, and a manually-operated circuit-closer for said generator.

16. The combination with a motor, of a controlling system therefor, a generator connected to run with the motor, a secondary source of current dependent upon said generator, and circuits and connections to effect the operation of said controlling system by current from said generator constant in value at starting but variable in strength in proportion to the speed of the motor for the further operation of the'controlling system.

17. The combination with a motor, of a controlling system therefor, a generator connected to run with the motor to produce current constant in value in starting the controlling system but variable in strength in proportion to the speed of the motor for the further operation of the controllingsystem,

and a secondary source of current dependent upon said generator.

18. A motor, a controlling system "there-,

for, a generator connected to run with the motor, said controlling system arranged to be operated by the current generated by said generator, said current being constant m value in starting the controlling system but variable in strength in proportion to the speed of the motor for further operation of the controlling system, and-means for maintaining the current at constant value in starting the controlling system.

19. A motor, a generator connected to run with the motor, a brake for the motor, an electrical circuit for the brake, magneticallyactuated starting-switches, and means operated by said starting-switches for controlling the circuit for the brake.

20. A motor, a generator connected to run with the motor, a brake for the motor, an electrical circuit for the brake, manually-actuated starting-switches, and means operated by said starting-switches for controlling the circuit for the brake.

21. A motor, a enerator connected to run with the motor, a attery in circuit with said genera-tor, a magnetically-actuated reversing-switch for the motor, two clrcmts for said magnetic 'means, one of which is arranged to be connected to the battery and the other of which is connected to the generator.

22. A motor, a enerator connected to run with the motor, a attery in circuit with said generator, a magnetically-actuated reversing-switch for the motor, two circuits for said magnetic means, one of which is arran ed to be connected to the battery and the ot er of which is connected to the generator, and means for automatically cutting oil the battery whenthe current of the generator reaches a desired strength.

23. A motor, a enerator connected to run generator, a magnetically-actuated reversingswitch for the motor, two circuits for said magnetic means, one of which is arran' ed tobe connected to the battery and the ot er of which is connected to the enerator, and a 'manually-o erated circuit-c oser to control sources of direct-current supply for said cir,

cuits, one of which is constant in value and the other of which varies in strength in proportion to the speed of the motor.

25. A motor, a generator connected to run with the motor a reversing-switch for the motor, magnets for actuatin the reversingswitch, two circuits for sai magnets, two sources of direct-current supply for said circuits, one of which is constant-invalue and the other of which varies in strength in proportion to the speed of the motor, and a manually-operated circuit-closer for controlling both of said sources of supply.

26. The combination witha motor,- of a generator, connected to run with the motor, -a

brake for the motor, a secondary source of current, and circuits and'connections to effeet the operation of said brake entirely b the current from said generator and-secon ary source of current.

- practical] 27. A motor, a generatorconnected-to run wlth' the motor, a brake for the motor, two

windings for said brake, one winding ar-.

ranged to be energized by a direct current of constant value to release the rake an the other winding arranged to be energized by a direct current of variable voltage proportional in strength to the s eed of the motor to'hold the brake in release position. p

28'. A motor, a generator connected to run with the motor, a brake for the motor, two

windings for said brake, one winding, arranged to be energized b a direct current of practicall constant va us to release the rake an the other arranged to be energized by 'a direct current of variable voltage proportional in strength to.thes eed of the motor .to hold the brake in-release osition, and means for. cutting off .said; st current when said second current hasreached a desired strength;

29. A motor, a generator connected to run with the motor, a brakefor the motor, twp windings for said brake, one. winding 'arranged to be energized'by .a "direct'current of practicallyconstant value to release the br e and the other arranged to be energized by a direct current of variable voltage proportional in strength to the s eed of the motor to hold the brake in release position, and manually-operated means for con-, trolling both currents. r

30;. A motor, agenerator connected to run. with the motor arranged to generate a current proportional in strength to the speed of arranged to generate a current proportional in'strength to the speed of the motor and to control said controlling device, and manuallyoperated means for rendering said generated current operative or inoperative.

33. In a motor-controlling system, a motor, a source of electrical energy connected to the motor, a generator connected to run with the motor, and arranged to generate a current proportional in strength to the speed of the motor, and magnetic means in circuit with I said generator arranged to; disconnect the source of supply from the motor, when the .motor reaches an excessive speed.

34. A motor, a generator connected to run with the motor, and a switch comprising contacts and circuit-closers for the motor, said switch adapted to be manually o erated, and 'a magnetic actuator 'rnechanica y connected to said switch, and electrically connected to the generator.

35. A motor, a generator connected to run with the motor, and a switch comprising contacts and circuit-closers for the motor, said switch adapted to be manually operated, and a magnetic actuator mechanically connected to said switch, and electrically connected to the generator and arranged to be operated by the current of the generator in proportion to the speed of the motor.

36. A motor, a generator connected to run with the motor, and a switch comprising contacts and circuit-closers for the motor, said switch adapted to be manually operated, and

:a magnetic actuator mechanically connected to said switch, and electrically connected to, the generator and arranged'tobe 0 erated by the current of the generator step h in proportion to the speed of the motor.

37. A motor, a magneticallyactuated starting-switch for the motor, a manuallyoperated circuitcloser for the startingswitch, a generator connected to run with the motor, and a switch comprising contacts and circuit-closers for the vmotor, said switch adapted to be manually operated, and a magnetic actuator mechanically connected to said switch, and electrically connected to the generator.

38. A motor, a manually-operated reversy step I ing-switch for the motor, a generator connected to run with the motor, an accelerating device for the motor, a magnetic actuator mechanically connected to the accelerating device and electrically connected to the generator, arranged to be operated by the current of the generator in proportion to the speed of the motor.

39. A motor, a generator connected to run with the motor, and a switch comprising con- 41. A motor, a reversing-switch for the motor, means for electrically operating said reversing-switch from a distance, additional means for manually operating said reversingswitch from a distance, a generator con nected to run with the motor, an accelerating device for the motor, a magnetic actuator mechanically connected to the accelerating device and electrically connected to the generator, and means for manually operating the accelerating device from a distance.

42. A motor, a generator connected to run with the motor, a controlling device for the motor, a magnetic actuator comprising one coil and a series of cores, said actuator being mechanically connected to the controlling device and with its coil electrically connected to the generator and arranged to be operated step by step by the current of the generator in proportion to the speed of the motor.

43. A motor, a generator connected to run with the motor, a controlling device for the motor, a magnetic actuator comprising one coil and a series of cores, said actuator being mechanically connected to the controlling device and with its coil electrically connected to the generator and arranged to be operated step by step by the current of the generator in proportion to the speed of the motorin one direction, and means for operating the controlling device in the opposite direction.

44. A motor, a generator connected to run with the motor, a controlling device for the motor, a magnetic actuator comprising one coil and a series of cores of different lengths and set in different positions within said coil, said actuator being mechanically connected to the controlling device and with its coil.

electrically connected to the generator and arranged to be operated step by step by the current of the generator in proportion tothe speed of the motor.

45, A motor, a generator connected to run mechanically connected to the controlling device and with its coil electrically connected to the generator and arranged to be operated step by step by the current of the generator in proportion to the speed ofthe motor and to thereby store up ower which power is arranged to operate the controlling devices in the opposite direction.

46. A motor, a generator connected to run with the motor, a controlling device for the motor, a magnetic actuator comprisin one coil and a series of cores, said actuator eing mechanically connected to the controlling device and with its coil electrically connected to the generator and arranged to be operated step by step by the current of the generator in proportion to the speed of the motor in one direction, and means comprising a spring 1n which power is stored up by the movement of the actuator for operating the controlling device in the opposite direction.

47. A motor, a generator connected to run with the motor, a battery, magnetically-ac tuated switches for the motor, said switches being actuated by current from the battery and held by current from the generator, a controlling device for the motor, a magnetic actuator mechanically connected to the motor-controlling device and electrically connected to the generator, said controllin device comprising contactsv which contro the battery and generator-currents.

48. A motor, a generator connected to run with the motorand arranged to generate a current proportional in strength to the speed of the motor, a battery, magnetically-actw ated switches for the motor, two sets of 0 erating-crcuits for said switches, one of w oh sets is arranged to be energized by current from the battery and the other of which 18 arranged to be energized by current from the generator, a controlling device for the motor, a magnetic actuator mechanically connected to the motor-controlling device and electrically connected to the generator, and meansating-circuits for said switches, one of w 'ch' sets is arranged to be energized b current from the battery and the other of w ch is arranged to be energized by, current from the generator, a controlling device for the motor.

a magnetic actuator mechanically connected In testimony whereof I have signed my to the motor-controlling device and electricname to this specification in the presence of lo all coriiefitedbfl the generatorl'i and meanfis two subscribing Witnesses. actuate t ere y or automatica ycuttin 0 v 5 the battery-circuits when the current of the AXEL MAGNUSON' generator reaches a re'determined strength Witnesses:

and for connecting t e battery to the gener- JOSEPH E. CAVANAUGH,

ator. v a l ERNEsT W. MARSHALL. 

